Hey, it's Flora Lichtenen, and you're listening to Science Friday.

Today in the show, how a mega-popular reality show offended what scientists thought they knew about metabolism.

I was interested in participating as a researcher, observing these folks who were doing this sort of natural experiment,

a study that couldn't have been done otherwise had they not already been signing themselves up for this kind of abuse on a national television show.

Remember the biggest loser?

That show where people tried to lose as much weight as quickly as possible for a big cash prize.

The premise of that show was that weight loss was about willpower.

With enough discipline, anyone can have the body they want.

Do not be sloppy.

Finish this strong, Joelle.

No, Joelle, don't do it. Don't do it. Don't do it. Dig,

Joelle, dig! The show had issues, and it hasn't aged well. And while the weight loss landscape has gotten more complex with GLP1 drugs like OZempic and Wagovi, a social media-fueled wellness industry, infinite fad diets. The underlying idea that weight loss

and health is as simple as Move More Eat Less hasn't gone away. But does that match current research?

How is our understanding evolved? A new book written by a journalist and a nutrition scientist, who, among other things,

studied Biggest Loser contestants, breaks down the science of nutrition and metabolism and what we've

learned in the two decades since that show premiered. The book is called Food Intelligence,

and I want to bring on the authors. Dr. Kevin Hall, nutrition scientist and former NIH researcher based in Kensington, Maryland,

and Julia Ballou's science journalist based in Paris. Welcome to both of you to Science Friday.

It's a pleasure to be here. Thanks for having us. Okay, let's start with this. What is food intelligence?

Well, the title's really a play on the idea that people really have a pun intended hunger

for knowledge about what it is that they're eating and how it works inside their bodies

and what it means for health.

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